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blackburn mark
20-09-2011, 06:52 PM
Iv added another diy brushless spindle to my growing collection and thought id post my adventures just in case anyone was in the market for a quiet spindle with low rev torque for cutting plastics and aluminium on a router

my large ER11 spindle has been a top notch work horse and has been the one I use 90% of the time, its taken some heavy abuse even on one occasion cutting two 30mm holes through 20mm of aluminium
with a hole saw... slow and painful but it got me there in the end :eek:

I have on occasion found the ER11 collets limit tooling choices e.g. dove tail/t-slot cutters, thread mills and slit saw arbours tend to have shaft diameters larger than the ER11 capacity of 7mm

Iv managed to procure myself an ER20 C10 collet shaft sooooooo.... I hope to replicate the success of the first spindle with a few minor mods and the ER20 (up to 13mm capacity)

its still a really simple design, the original has one 3200 double row angular contact bearing in the nose, this one will have two 3200 double row angular contacts aprox 10mm apart in the nose and should stop any of the standard motor bearing slop transmitting to the tool end of things.... in reality I cant imagine ill see a difference as the MK 1 spindle works pretty well but I might as well, the theory is there and the bearings are cheep :)

it amazes me that more people have not built this type of spindle but I guess most of you are cutting wood but for anyone cutting plastics and aluminium on a router they make a lot of sense

this one I run on a 12v 350w power supply and get 2800rpm flat out and it maintains enough torque down in the mid hundreds(rpm) to deal with anything iv thrown at it... I know I have vastly under powered it but at 12v the speeds are good and the temperatures (motor windings/bearings and speed controller) remain sensible, besides that, any more power would be wasted on my machines inability to dampen the low frequency resonance.
6mm 4 flute carbide is about my limit when cutting aluminium and with a 60mm radius fly cutter ill get resonance patterns down wind of any holes I pass over unless I take it very easy
(errrrrrrr.... if any of that makes any sense) :smile:

£17:50 100A Brushless Motor Speed Controller RC BEC ESC (make sure you get the BEC version of any speed controller as it eliminates any need for a 5v supply to your servo tester/controller)
£17:09 C10 ER20 100L collet chuck CNC extention shank
£15:00 FOR TWO 3200/5200 DOUBLE ROW ANGULAR CONTACT BEARING 10X30X14
£ 1:89 New RC Helicopter Plane CCPM Servo ESC Checker Tester
£35:11 XYH63-54 250KV 65A Outrunner (excluding postage... cant remember)

(there is a cheep as chips outrunner on ebay for £16:60 delivered
"Outrunner Motor C6364 KV230 Brushless for RC Airplane"
but the one I got was very poorly balanced, the bell was out of true
by a degree or so and I didn't want to bother my arse trying to square it up)

£86:59 (ish) + some elbow grease a couple of lumps of ally and a 12v power supply

in order to get the second bearing pocket square with the first I milled it out under size fitted the first bearing and the ER20 chuck and put the whole assembly in the lath and skimmed the last 0.5mm with a small boring tool then skimmed the outer body to 43mm... worked a treat, all nice and square :)

460745974596


4609
removing the exsiting spindle shaft can be a pain but this one came out pretty easy
4604
cut one of the bearing recesses to a press fit and you should be able to part assemble
your spindle and skim the second bearing recess to an almost perfect alignment

4598
the ring with the six holes is there to extend the clamping aria to make it compatible with my exsisting spindle clamp and is not esential (it will help keep the crap out though and looks posh):wink:


4601
part assembled again to skim out where the bearing housing sits to a tight true fit

4603
servo controller and 100A ESP


4599
almost finished.... just needs some drilling and tapping to lock the bearing housing to the acetal mount and were off :smile:

4600
looking at this photo has me thinking im developing a bit of a fetish for these brushless motors :twisted:
the blue motor is the "cheep" one that has an extreamly out of balance bell, also in my rush to get it finished i managed to take to much material off the bearing body and had to use aluminum tape to shim it out to fit my clamp :redface: its seen me though a couple of tight spots though and will now be retired as a spare

the small one will run up to a theoretical 48000rpm on 12v but i cant see the bearings lasting long at that speed, i keep daring myself to test it to destruction but i just cant bring myself to do it and i get by with it running below 20000rpm
the yellow one will run upto 10000rpm and i tend to use that for tool grinding
4605

4606
exsample of some of the work done with these spindles... i love cutting acetal :smile: and i love thread milling M3 in acetal, if things go awry you tend not to snap the tool....
thread milling should be re classified as an extream sport.... its WELL exciting :eek:... or is that just me being sad ?

Rogue
20-09-2011, 07:09 PM
Interesting and intriguing!

Jonathan
20-09-2011, 07:57 PM
The thing to do with your collection of spindles is index them ... rotary table on the Z-axis with the spindles each mounted 72° apart then just spin it to the one you want - like on a CNC lathe. That basically gets you an automatic tool changer. The only potentially difficult bit is locking the rotary table automatically...and maybe the wiring! Hmm you've given me a project now, as if I didn't have enough to make! Use some sort of rotary switch, or just 5 microswitches to activate each spindle automatically. Even snazzier is if the motors are similar you can use one ESC for the lot, and a bunch of relays to switch between spindles...

I should probably use mine more now I'm almost invariably cutting aluminium on my router. It's only 6000rpm (allegedly 6kW) though which is about half what I'd like...

4612
4613
4614

How much difference do you think using the two double row bearings made versus one? Mine has one double row and something like (can't remember) 5 standard bearings.

Jonathan
20-09-2011, 08:05 PM
This motor looks like the same as what you used, and it's cheap:

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=5144

I'm tempted to get at least 3 of them, plus one ESC, and mount them all along with my existing spindle.

http://www.ebay.co.uk/itm/C10-ER20-100L-collet-chuck-CNC-extention-shank-US-/270719881204?pt=BI_Tool_Work_Holding&hash=item3f08298ff4#ht_1682wt_1037

Could get a bit expensive...

blackburn mark
20-09-2011, 08:26 PM
The thing to do with your collection of spindles is index them ...


hahaha! yep it did cross my mind man but i tend to use the 2000W spindle for almost everything i do and changing spindles is a moment of a job



How much difference do you think using the two double row bearings made versus one? Mine has one double row and something like (can't remember) 5 standard bearings.


i havnt cut anything with the new one yet jonathan, i was well happy with the old one, i belive it could out perform my machine with the single double row in it but as i was building a new one it seemed silly not to add the second bearing if i could suss a way of keeping the resses perfectly true.... it was a nice surprise when i fitted the shaft and there wasnt any extra friction due to missalignment (its a tough nut to crack)

it will be interesing to see if there is any inprovement but im sure the resonance paterns i get are from my gantry sides

blackburn mark
20-09-2011, 08:33 PM
This motor looks like the same as what you used, and it's cheap

NICE.... its a bit better than mine.... i must resist i must resist i must... you bugger jonathan!!!!! iv got enough brushless motors

the ER spindle you linked is the one i bought... took about three weeks to turn up but you cant go wrong at that money :)

Jonathan
20-09-2011, 08:39 PM
hahaha! yep it did cross my mind man but i tend to use the 2000W spindle for almost everything i do and changing spindles is a moment of a job

So make more of those ... the prospect of not changing tools manually would be worth it for me. That and it'd look pretty awesome.


NICE.... its a bit better than mine.... i must resist i must resist i must... you bugger jonathan!!!!! iv got enough brushless motors

Resist that one and get this one, it's 280kV so a bit faster!

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=2097

Looking forward to a video of the new one running...

blackburn mark
20-09-2011, 11:19 PM
So make more of those ... the prospect of not changing tools manually would be worth it for me. That and it'd look pretty awesome.

i could murder you jonathan!!

the power and switching would be the easy part... just make interupted slip rings driven by one ESC

the tricky bit is making the capstan rigid without it weighing a ton and having a masive overhang

i dont believe youv got me thinking on this one... iv also got a million and one things going on :eek: "i must get some sleep at least once this week":eek:

it would be nice to have a 5x tool change though:smile: i could go down the pub swill a couple cut the lawn smoke a couple have a manicure come home change slabs have a couple of hours sleep.............zzzzzzzzzzzzzzzzz............

i may ponder this some more but i can sniff a bit of a blind alley coming on :wink:

njhussey
25-10-2011, 11:26 PM
Hi Guys...

I've just started to build my router again after a years lay off (got into RC Helis which I fly in B'burn which ate/eats up all my money and sparetime) and have a servo tester (for setting the CCPM swash on the heli up) and spare a few spare ESCs so this is looking interesting!! To start with I'm only looking to cut balsa and ply but as time goes on I'll want to cut plastic and maybe some Ali (when I've made mods to my router.) What would your suggestions be for motor etc? I was thinking of something a little smaller than yours, something like http://www.giantcod.co.uk/xyh5065-270kv-brushless-outrunner-p-404605.html with a http://www.ebay.co.uk/itm/C8-ER11-100L-Straight-Milling-Lathe-Chuck-Holder-US-/160656485801?pt=BI_Tool_Work_Holding&hash=item2567df6da9 we have an old Colchester Bantam lathe at work so could have a go at the bearing housing...

Cheers, Neil.

blackburn mark
26-10-2011, 04:11 AM
hi neil, sounds like youll have no problems with the project:smile:

id be tempted to go with an ER11 C8 with a little less overhang

http://www.ebay.co.uk/itm/ER11-8MM-STRAIGHT-SHANK-COLLET-CHUCK-CNC-MILLING-LATHE-TOOL-WORKHOLDING-D66-/150676636475?pt=BI_Tool_Work_Holding&hash=item231507033b

if you compare this with the one you linked i think youll know what im driving at... it may make little diffrence when cutting balsa but when aiming to cut ali every little bit of stiffness you can gain will help (i have cut ali with mine)

iv used cheep skate bearing in my ER C8 spindle... iv used belleville washers to put some tention between the two outer races.... i havnt had to change them yet but it only gets light use

if you dont put any tension on those skate bearings the balls will skid and self destruct pretty quickly

4771
the layout is not to clear in this picture, youll have to let me know if you dont get it :wink:

njhussey
26-10-2011, 12:46 PM
Thanks for the info Mark I'll have a look at that one. Instead of cheap skate bearings could I not use a single double row AC bearing, would I have to pre-tension it? Saying that I've skate bearings coming out of my ears as I'm planning on using them as the linear bearings on all my axis ;) The only problem I can see for me is making the bearing housing, I looked at our lathe this morning and the tooling is crap as it's only used to take the raised face off flanges etc, not sure when it last had a service either. Will get some Ali bar offcut and have a play I think. Hope it's ok as I was planning on machining my leadscrews on it!

njhussey
26-10-2011, 03:40 PM
From a quick search on tinternet it seems that most double row angular contact bearings seem to start at 10mm ID so looks like its the skate bearing route for me...

Jonathan
26-10-2011, 04:16 PM
Yes I looked for a while for 8mm angular contact bearings but only found one supplier, on eBay in america and not cheap. That was for single row, couldn't find any double row that size.

http://www.ebay.co.uk/itm/708A-8mm-Spindle-8x22x7-Angular-Contact-Ball-Bearing-/400216442464?pt=LH_DefaultDomain_0&hash=item5d2ec24660#ht_560wt_905

I wouldn't expect normal bearings to last long if you're drilling ... but nobody really cares as they're so cheap.

Also you can get ER16 collet chucks with 8mm shank:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=110758136203#ht_4690wt_1080


Saying that I've skate bearings coming out of my ears as I'm planning on using them as the linear bearings on all my axis ;)

That's slightly worrying - depends how you go about it.


...making the bearing housing, I looked at our lathe this morning and the tooling is crap as it's only used to take the raised face off flanges etc...

Poor workman blames his tools :whistling:

njhussey
26-10-2011, 04:51 PM
Yes I looked for a while for 8mm angular contact bearings but only found one supplier, on eBay in america and not cheap. That was for single row, couldn't find any double row that size.

http://www.ebay.co.uk/itm/708A-8mm-Spindle-8x22x7-Angular-Contact-Ball-Bearing-/400216442464?pt=LH_DefaultDomain_0&hash=item5d2ec24660#ht_560wt_905

I wouldn't expect normal bearings to last long if you're drilling ... but nobody really cares as they're so cheap.

I'm only cutting balsa and ply to start with so they will do, but then for the little extra it would cost might be worth getting a larger motor and 10mm spindle?


Also you can get ER16 collet chucks with 8mm shank:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=110758136203#ht_4690wt_1080


Looks good, will give more tooling options later on...



That's slightly worrying - depends how you go about it.
Going down the skate-o-rail option or might just do a quick and dirty joe2006 type to get it up and running...yes I know, i know, i know but I'm doing it on the tightest budget I can and will then upgrade to supported rail etc when I can afford it.



Poor workman blames his tools :whistling:Well they're not my tools...but will put an order into RDG for some new ones....unless one of you two fancies giving me a price for making the bearing holder????

HankMcSpank
26-10-2011, 06:58 PM
I maintain there's a tidy little sideliness/embryonic business for someone with the nous to start supplying these brushless spindles in decent numbers to the hobbyist CNC market.

At the minute a CNC hobbyist is faced with Dremel (eeugh) proxxon (nicer but feeble) ...then a leap up to something like kress (good but probably a bit too loud for most...and the price is starting to get chunky).

I reckon if you could knock these out somewhere in between the Proxxon price level (about £90) & Kress level (£150?) ...there'd be good steady demand.

Jonathan
26-10-2011, 08:19 PM
I maintain there's a tidy little sideliness/embryonic business for someone with the nous to start supplying these brushless spindles in decent numbers to the hobbyist CNC market.

I'd happily make lots of them, but I've not got time now with being at University.
I will probably make some in the holidays. The issue is which motor to choose as it's always a compromise between collet size and max rpm. The ideal way to do it is get a motor which will take an ER20 chuck and rewind it to get the required, higher, rpm (well, kv strictly).

blackburn mark
26-10-2011, 11:03 PM
i bought a pair of those 708A bearings but never got around to implimenting them as i ended up using the larger spindles most of the time and the skate bearings seem to be holding up to the amount of use that they get

the 8mm shaft motors make sense if your cutting balsa because of the higher KV choices



I maintain there's a tidy little sideliness/embryonic business for someone

i did mull the idea for a spell as i belive the larger brushless spindles would knock the knickers off a kress or even one of those posh water cooled chinese jobs at cutting ali and plastics (especialy so if your finishing with a fly cutter) but i get the feeling most people are after cutting wood on their cnc routers and stick to small tooling to cut the odd bit of alli so im not sure there would be a demand myself



From a quick search on tinternet it seems that most double row angular contact bearings seem to start at 10mm ID


yep! its a crying shame you cant get them smaller :cry: they work like a charm and make the job eeeeasy!!! :smile:

njhussey
26-10-2011, 11:33 PM
Yes I looked for a while for 8mm angular contact bearings but only found one supplier, on eBay in america and not cheap. That was for single row, couldn't find any double row that size.

http://www.ebay.co.uk/itm/708A-8mm-Spindle-8x22x7-Angular-Contact-Ball-Bearing-/400216442464?pt=LH_DefaultDomain_0&hash=item5d2ec24660#ht_560wt_905



Well what the hell....decided to buy a couple of these as they will last longer and will be better than the skate bearings. Will get the other bits as and when I sell more velcro on fleabay and get more money in.

Mark / Jonathan are either of you up for making a bearing housing for me?? For a price of course....

blackburn mark
27-10-2011, 12:00 AM
Well what the hell....decided to buy a couple

have you worked out a posh (easy) way to keep the lube in and the crap out of these un-sealed bearings ? its one of the reasons i havnt used mine yet :)



Mark / Jonathan are either of you up for making a bearing housing for me?? For a price of course....

im up to my neck at the moment so hopfully jonathan will pick this up... you will need two stepped washers making unless you can find belleville washers that are 22mm (just under 22mm so they clear the inner housing)
it is probably a good idea if you do a drawing so you can thrash out any problems you might have

njhussey
27-10-2011, 12:20 AM
have you worked out a posh (easy) way to keep the lube in and the crap out of these un-sealed bearings ?

I was going to get them and then spend the time whilst they wing their way from the US looking at ways to do it :-)



im up to my neck at the moment so hopfully jonathan will pick this up... you will need two stepped washers making unless you can find belleville washers that are 22mm (just under 22mm so they clear the inner housing)
it is probably a good idea if you do a drawing so you can thrash out any problems you might have

I might buy a 50mm dia offcut of Ali and have a tinker on the lathe at work, will check to see if we have any boring tools to play with!

blackburn mark
27-10-2011, 12:29 AM
I was going to get them and then spend the time whilst they wing their way from the US looking at ways to do it :-)


a man after my own heart :)



I might buy a 50mm dia offcut of Ali and have a tinker on the lathe at work, will check to see if we have any boring tools to play with!

thats more like it :) if you over size the bore just slap a bit of epoxy in there it should easily take the cutting force (just dont use your posh bearings on that one lol

njhussey
27-10-2011, 12:43 AM
Just bought 2 off 2" dia x 50mm bits of Ali.....one to mess about with and the other to do the propper job :whistling:


I was going to get them and then spend the time whilst they wing their way from the US looking at ways to do it :-)

I'd best get started then as just been informed that they've been shipped :eek:

blackburn mark
27-10-2011, 12:50 AM
Just bought 2 off 2" dia x 50mm bits of Ali.....one to mess about with and the other to do the propper job :whistling:



hahahahahaha!!!!!! i think me n you might have been separated at birth :rofl:

njhussey
27-10-2011, 01:03 AM
Well they say you're supposed to measure twice, cut once........never works for me :confused: so I get twice what I need and mess the first one up :naughty:

John S
27-10-2011, 01:14 AM
Yes I looked for a while for 8mm angular contact bearings but only found one supplier, on eBay in america and not cheap. That was for single row, couldn't find any double row that size.



In the smaller sizes they are known as magneto bearings, Arc keeps them, ask for E8's

njhussey
27-10-2011, 01:33 AM
Cheers John, when you know what they're called they're everywhere!! Still got to work out how to shield them.......

Jonathan
27-10-2011, 02:00 AM
In the smaller sizes they are known as magneto bearings, Arc keeps them, ask for E8's

Hmm, I even looked there... must be blind:

http://www.arceurotrade.co.uk/Catalogue/Bearings/Angular-Contact-Ball-Bearings


Still got to work out how to shield them.......

Aluminium disk or whatever with only a very very small clearence - enough to stop it touching, but not so big that it lets lots of dust in. I believe the term is aluminium labyrinth. Any seal which touches is going to generate a lot of heat due to friction.

njhussey
27-10-2011, 08:46 AM
Hmm, I even looked there... must be blind:

http://www.arceurotrade.co.uk/Catalogue/Bearings/Angular-Contact-Ball-Bearings

Or...

http://simplybearings.co.uk/shop/p42606/E8+Magneto+Bearing+8x24x7mm/product_info.html

or...

http://www.ebay.co.uk/itm/E8-MAGNETO-BEARING-8-X-24-X-7MM-E-8-/200498922371?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item2eaeaac383

etc.....etc...


Aluminium disk or whatever with only a very very small clearence - enough to stop it touching, but not so big that it lets lots of dust in. I believe the term is aluminium labyrinth. Any seal which touches is going to generate a lot of heat due to friction.

Was going to see if I could reverse engineer a shield like on the 608RS bearings....or how about http://simplybearings.co.uk/shop/p24069/8x24x7mm+Nitrile+Rubber+Rotary+Shaft+Oil+Seal+R21+/+SC/product_info.html but not sure what speed it's rated to....food for thought anyway!

Jonathan
27-10-2011, 10:48 AM
Or...

http://simplybearings.co.uk/shop/p42606/E8+Magneto+Bearing+8x24x7mm/product_info.html

or...

http://www.ebay.co.uk/itm/E8-MAGNETO-BEARING-8-X-24-X-7MM-E-8-/200498922371?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item2eaeaac383


Yes, easy once you know...




http://simplybearings.co.uk/shop/p24069/8x24x7mm+Nitrile+Rubber+Rotary+Shaft+Oil+Seal+R21+/+SC/product_info.html but not sure what speed it's rated to....food for thought anyway!

I doubt rubber seals are appropriate for the speed this will be running at. The bearings apparently already get hot, so a seal like that is just going to make it worse. I used some on my wind turbine, for each blade, and they add a lot of friction...but it didn't matter there as it's only a few rpm.

njhussey
27-10-2011, 11:11 AM
I doubt rubber seals are appropriate for the speed this will be running at. The bearings apparently already get hot, so a seal like that is just going to make it worse. I used some on my wind turbine, for each blade, and they add a lot of friction...but it didn't matter there as it's only a few rpm.

Just found out they are only good for 1000 rpm....damn!!! Just had a brainwave tho! Will contact our pump suppliers and see what they use...if they run them a 2 pole then that's 2900 rpm so might be better...will put some feelers out.

njhussey
27-10-2011, 03:12 PM
Just been trying (and I stress trying!!!) to do some machining of my lead screws in my lunch break...think I'll get someone else to do it! The jaws are worn and it takes ages to get them to clamp so it spins true and I had to shim the cutting tool so it was somewhere near the correct height...results of 3/4 hr below lol

blackburn mark
28-10-2011, 02:49 PM
Just been trying (and I stress trying!!!) to do some machining

owch!
you need to hassle your gaffer to let you do a nip n tuck on that lath :smile:

it might cut alli a bit better than that (fingers crossed)

what outside diameter are you going for on your bearing housing ?
i went for 43mm so that if it all didnt work out with my brushless spindles i could just drop a kress into the 43mm clamp..... its worth doing some research because if i was starting again i think would go slightly larger than 43mm to avoid an issue whereby the brushless motor mounting screws (on the larger motor) clash with the 43mm di making it a bitch to simply drill all the way through or cut a flange to mount the housing to the motor (i think the 10mm shafted motor mounting screws are 22mm from the centre)

its worth thinking about because if i had gone 50mm as a standard for all my spindles life might have been a little more simple

4786
i ended up turning the 50mm one down to 43mm to match the other two

njhussey
28-10-2011, 03:06 PM
owch!
you need to hassle your gaffer to let you do a nip n tuck on that lath :smile:

it might cut alli a bit better than that (fingers crossed)

hmmm I'll try one (need to buy a boring bar as don't have one) and see what happens. From the finish I got you'd have thought I'd stuck it in a drill and used a file!!


what outside diameter are you going for on your bearing housing ?
i went for 43mm so that if it all didnt work out with my brushless spindles i could just drop a kress into the 43mm clamp..... its worth doing some research because if i was starting again i think would go slightly larger than 43mm to avoid an issue whereby the brushless motor mounting screws (on the larger motor) clash with the 43mm di making it a bitch to simply drill all the way through or cut a flange to mount the housing to the motor (i think the 10mm shafted motor mounting screws are 22mm from the centre)

its worth thinking about because if i had gone 50mm as a standard for all my spindles life might have been a little more simple

4786
i ended up turning the 50mm one down to 43mm to match the other two

Weeeeell....as it happens I've bought 50mm rounds so was going to stick to that...got to see if they've got the external jaws first else I'll get one of our local friendly machinists to make it...

njhussey
31-10-2011, 02:22 PM
Got my 2" Ali pieces today, too late to do any machining in my lunch break but might come in early tomorrow to have a play :naughty:


iv used cheep skate bearing in my ER C8 spindle... iv used belleville washers to put some tention between the two outer races.... i havnt had to change them yet but it only gets light use


Mark, where did you get your belleville washers from? Was going to stick a couple in between my single row AC bearings?

njhussey
31-10-2011, 04:10 PM
I'll have to wait until I get the motor for the through mounting hole dimensions but was thinking of something along these lines.....

blackburn mark
31-10-2011, 05:56 PM
Mark, where did you get your belleville washers from? Was going to stick a couple in between my single row AC bearings?


eeeerrrr, dunno?? pretty sure i got them on ebay.... i just did a search and they are all coming up USA which is a bit of a bind, iv got some left (8.2mm inside 18.9mm outside diameter) so measure the distance your going to have between your bearings ill send you enough to fit that gap (n youll owe me a favour :smile:... its not the washers, its the dragging my arse over to the post office that youll owe me for :wink:)

iv used 12 washers and compressing them about 0.5mm (very light, less than 1kg) i guess you could be a little more aggressive with those A/C bearings but im not sure to what advantage ?? id play it safe and keep it light... if you get any signs of movement slop chatter add a shim etc.

njhussey
31-10-2011, 06:18 PM
I've found some at Bellville Springs...Part code: D18842
Price: £10.33 per 100 pcs, Postage: £5.50 with a min order charge of £15...could always flog the rest on fleabay lol.

I think I've left a 3mm gap between the bearings atm but am open to suggestions!

blackburn mark
31-10-2011, 07:17 PM
I think I've left a 3mm gap between the bearings atm but am open to suggestions!

your not going to get many washers in there :eek:

id try to get them a little further apart so you can get at least a few pairs of washers twixed

i know its a bit late now but if i was starting from scratch id use up the full length of the ER shaft
i didnt do this on mine, i have 22mm of shaft protruding out of the motor bell, i could have made the bearing bell 22mm longer utilsing the theoretical extra stability however the best performing spindle i have only has one double row A/C at the nose so i guess the diffrence may be negligible for our aplication

the new ER20 with two double row is suffering with resonance when cutting quite hard at the moment, something is rolling or skidding in there.
that should stop when i do my final strip and loctite.... errr.... maybe

njhussey
31-10-2011, 07:54 PM
Well if I'm going to use the ER16 x 8mm (http://www.ebay.co.uk/itm/ER16-8MM-STRAIGHT-SHANK-COLLET-CHUCK-CNC-MILLING-LATHE-TOOL-WORKHOLDING-F88-/110758136203?pt=BI_Tool_Work_Holding&hash=item19c9b3098b) then I've got 100mm of shaft to play with. The motor I'm proposing to use (http://www.giantcod.co.uk/xyh5065-320kv-brushless-outrunner-p-404606.html) is an XYH 50-65 so 50mm dia and 65mm long, that only leaves me 35mm to play with. If I have a 5mm cap/lid (whatever) and leave 3mm at the back I'll have 28mm to house the bearings (7mm wide each) and the belleville washers so I'll have 14mm to fill up....better or too much?

Getting into Google Sketchup now, but takes a long time to draw anything as my laptop is slowwwwwwwwwwwwwww..........

blackburn mark
31-10-2011, 08:22 PM
so I'll have 14mm to fill up....better or too much?

sounds better to me :)



Getting into Google Sketchup now, but takes a long time to draw anything as my laptop is slowwwwwwwwwwwwwww..........



worth it though... when im designing something with production in mind i can spend hours just looking at the same drawing to see if it can be stream lined or knock some of the pain out of production and make it look posh etc etc etc....

njhussey
31-10-2011, 08:48 PM
worth it though... when im designing something with production in mind i can spend hours just looking at the same drawing to see if it can be stream lined or knock some of the pain out of production and make it look posh etc etc etc....

Certainly is I find it usefull for visualising what somethign is going to look like. Gives you an idea whether it's going to work or not. Also use it at work to draw 3D (without having to get the DO involved) pics of what I'm quoting. Just starting to build up a library of standard parts. Slow progress tho as it has to be done in lunchtimes etc and I'm still trying to get into it....

njhussey
02-11-2011, 07:05 PM
Went to play with the lathe at lunch and was greeted with it in this state... Bloody hairy arsed fitters. Spent lunch cleaning and setting the tailstock up as it was miles out...never got to do any cutting!

Joe
04-11-2011, 09:43 PM
Hi Guys
I havedesigned and made a brushless spindle as well but my design is a big biggerthan most (overkill really) it has a FAG angular contact double row on thebottom and FAG standard bearing on the top with a 20mm shank ER16 collet chuckfrom ebay.

I waswondering what people use for the power supply as I fund that my 15Amp batterycharger doesn’t provide enough power.
The picture shows a drill chuck but that is being held by the ER16 chuck because i did not have the right size collet
4816
Joe

Jonathan
06-11-2011, 05:42 PM
Nowhere near as big as mine :)

What motor did you use...what power? Doesn't it accept more than 12v (assuming the battery charger you're using is 12v)?

A toroidal transformer (eBay) plus rectifier and some good low ESR caps would do nicely, but you might find it needs to be a bit large. Another option is a switching power supply ... which isn't cheap either unless you use old ATX (computer) power supplies. If it's 12V then just use one, if not you can put them in series - but check that they're isolated first to prevent fireworks.

My next spindle is going to have 2 or 3 motors 3kW motors on the same shaft, ER-20 up to 27000rpm (ish) and oil cooled. That's the only way I can work out to get the required rpm range and torque without rewinding (which I might need to do anyway). Wye/delta switching plus something else to get more torque options). Bought the motors a couple of days ago. Going to use FEA to model the friction due to oil cooling and optimise it ... then proceed.
Anyway, the relevant bit for you is I'm going to use 2 (or 4, depends) ATX PSUs in series, to get about 1kw input power, with a 3Ah Lipo battery placed in parallel, to take care of current peaks, as close as possible to the ESC (to minimise impedance). Will also replace the electrolytic capacitors on the ESC (which will be incorporated into the oil cooling) to an array of low impedance ones as that will make the ESC run a lot cooler.

Hope you're not milling with that chuck, or spinning it as fast as that motor might go.

blackburn mark
06-11-2011, 06:17 PM
I fund that my 15Amp batterycharger doesn’t provide enough power.



http://www.ebay.co.uk/itm/12V-30A-360W-Switch-Power-Supply-Driver-LED-Strip-light-Display-220V-110V-/150669039660?pt=UK_HomeGarden_Lighting_Lamps_Light ing_SM&hash=item231493182c

i bought somthing like this for mine, iv not tripped it out once so far :smile:



My next spindle is going to have 2 or 3 motors 3kW motors on the same shaft, ER-20 up to 27000rpm (ish)

:eek: on your router ?... i cant imagine a router making use of so much power, youve got me thinking cutting wood at high speed must soak up the spindle watts :eek:

i only ever cut alli and plastics and iv never needed any more than 360W... my top speed is only 1500mm though wich i guess is not worth getting out of bed for in "Jonathan world " :lol:

Jonathan
06-11-2011, 06:46 PM
[FONT=Arial]

http://www.ebay.co.uk/itm/12V-30A-360W-Switch-Power-Supply-Driver-LED-Strip-light-Display-220V-110V-/150669039660?pt=UK_HomeGarden_Lighting_Lamps_Light ing_SM&hash=item231493182c

i bought somthing like this for mine, iv not tripped it out once so far :smile:


Not bad, but a fiver down the car boot should get you a computer power supply which will deliver at least that. Just put a resistor on the +5V rail (google it) to keep it on and stable.


:eek: on your router ?... i cant imagine a router making use of so much power, youve got me thinking cutting wood at high speed must soak up the spindle watts :eek:]

Wood does with a good size cutter, but that's not the reason as I hardly ever cut wood an no DIY router is rigid enough to use that much power. Why use plywood when you can use 3/4" aluminium :smile:
It's for my friend from school who I will be helping (well, letting him use my router - he doesn't need help) build a smaller rigid machine to be used mainly for cutting aluminium and occasionally steel (hopefully)...knowing him probably titanium too. Anyway, the reason for that much power and the whole coil switching thing is to be able to get lots of torque at low rpm, which is useful for drilling/facing among other things. I don't expect to use anywhere near the full rated power of the motors.

Top speed 1500, mm/min? Is that rapid speed or top speed you use when cutting?

blackburn mark
06-11-2011, 07:00 PM
Top speed 1500, mm/min? Is that rapid speed or top speed you use when cutting?

owch!!! you buggar! kick a man while he is down lol ..... errrr... thats rapid, i am "slowly" coming around to the idea that a little more speed might help (what did it cost you for your drivers ???? and would i need to swap my 57BYGH76-401A steppers current 2.8A ???)




It's for my friend from school who I will be helping (well, letting him use my router - he doesn't need help) build a smaller rigid machine to be used mainly for cutting aluminium and occasionally steel (hopefully)...knowing him probably titanium too.

youve got to do a log on that jonathan!! :)

Joe
07-11-2011, 08:31 PM
The motor is a Thumper 5055, 10.8-29.6V, 1280 watts and 580 KV

Yes the motor does accept more voltage but the charger was the only thing that I had on hand. My Grandpa has an ex-school lab transformer that is 12v,100A which once rectified should provide more than enough power:smile: . I just need to find theright sort of low ESR caps, could you recommend any?

Do you think that if I up the current that the motor will be more powerfulor will I also need to up the voltage and use a different supply?

My spindle ESC also gets quite hot after running for more than about 15 mins as well, but nothing excessive. The spindle however gets very hot after beingrun for about 25 mins, I think that I will need to devise some sort of watercooling but I am going to try bigger and more fins and a fan first. The projec tis also my Product design coursework at collage so a big thank you for all your advice

Thank you blackburn mark for the ebay power supply I needed something like that for my audio set up and at that price you can't go wrong so I have ordered one :smile:

njhussey
08-11-2011, 04:46 PM
Bought a turning tool last week and did some turning of my second piece at lunch....much better results.

Got to buy a boring tool now as some ijit used it and has knackered it. Getting there slowly...

blackburn mark
08-11-2011, 05:09 PM
Now thats more like it :smile:

your already on your second peice of alli ???? owch :rofl: no pressure then :eek:

njhussey
08-11-2011, 05:35 PM
The second piece is for the cap, I've rough (rough bring the operative word!!) turned the first piece but should really have bought a longer piece of Ali...so I'm going to turn a shoulder in the end of the first piece to more accurately hold it in the jaws (so I can then finish machine out the jaw marks) then finish machine, bore it for the bearings and part off ( couldn't get the parting off tool near enough without hitting the jaws before)...

Well that's the cunning plan anyway ;-)

What's the easiest way to accurately drill the holes for mounting the motor without any sort of indexing head/table anyone?

blackburn mark
08-11-2011, 06:39 PM
What's the easiest way to accurately drill the holes for mounting the motor without any sort of indexing head/table anyone?

errrr? i did a bit of a hatchet job on my first one (not having cnc at that point)
scribed a line with a centre finder square... dot punched my first two holes then used my vernier calipers (one tip in the dot) and scribed a circumfrence from both dots trail and error style :)

it got me there (just)

make sure you mark and drill the face that is going to sit on your motor just in case your drill wanders.... i find it really easy to forget stuff like that :redface:

njhussey
08-11-2011, 08:32 PM
Well I was thinking of either buying one of these http://www.rdgtools.co.uk/acatalog/PROTRACTORS_ETC.html or drawing the bit in CAD, printing it out and sticking it on and centre punching the holes before drilling on the pillar drill, think I'll go the first way as the second seems a bit crude!!

Jonathan
08-11-2011, 08:41 PM
Well I was thinking of either buying one of these http://www.rdgtools.co.uk/acatalog/PROTRACTORS_ETC.html or drawing the bit in CAD, printing it out and sticking it on and centre punching the holes before drilling on the pillar drill, think I'll go the first way as the second seems a bit crude!!

No need to buy those... as Mark said all you need is dividers. Scribe a circle, or lightly touch the lathe tool to it whilst in the lathe to make a circle then use dividers to divide that circle equally - centre punch then a quick swing on the pillar drill. Equally nothing wrong with printing out a template and sticking it on - printers are pretty accurate.

If you've got access to a milling machine then just put it in the vice, center drill (or spot drill) in mill and mark out the holes with that. Zero the X/Y dials in the center, noting in what direction you zeroed them so you can compensate for the backlash by always turning to that point in the same direction. Move it the correct distance using CAD program or simple trig to find the distances.

There's many more ways to do it sufficiently accurately without buying anything.

njhussey
08-11-2011, 09:38 PM
No need to buy those... as Mark said all you need is dividers.

Hmmm... Dont have any but do have vernier calipers so might try that


Scribe a circle, or lightly touch the lathe tool to it whilst in the lathe to make a circle then use dividers to divide that circle equally - centre punch then a quick swing on the pillar drill. Equally nothing wrong with printing out a template and sticking it on - printers are pretty accurate.

Might have a go at one of those ways on some scrap bar..,


If you've got access to a milling machine then just put it in the vice, center drill (or spot drill) in mill and mark out the holes with that. Zero the X/Y dials in the center, noting in what direction you zeroed them so you can compensate for the backlash by always turning to that point in the same direction. Move it the correct distance using CAD program or simple trig to find the distances.

We have an old Bridgeport milling machine at work, not sure if it works though, will ask the guys tomorrow.

Cheers chaps, given me plenty to think about...

njhussey
11-11-2011, 09:53 PM
Well I've ordered the ER16 collet from fleabay http://www.ebay.co.uk/itm/ws/eBayISAPI.dll?ViewItem&item=110758136203&ssPageName=ADME:B:EOIBSA:GB:1123 and have had a go a boring the bearing housing. However my boring tool (went for the 10mm brazed tip boring bar http://www.rdgtools.co.uk/acatalog/Brazed_Boring_Bars.html) needs alot of grinding to get it to not rub...might see if I can grind one from scratch as we have a few lengths of tool steel lying around...still got probably 3 weeks to do it in before my ER16 collet arrives on these shores :smile: Thinking of which my bearings should be here from the US within the next week :tongue:

njhussey
25-11-2011, 08:37 PM
Collet arrived today :-) ...but still waiting for my bearings :-( Going into work early tomorrow to do a bit more (been doing 12 hr days at work recently so not had a chance to get more done tut) on the spindle and maybe even my machine!!

Villacherman
01-12-2011, 02:46 AM
Neil,

Great work so far on the spindle, I'm anxiously watching how it turns out. I'm building a similar spindle, however, I'm thinking of incorporating a v-belt pulley drive so if I want to change the speed/torque I can have that option. Does complicate things a little more.

My intent is primarily to machine aluminum and hard plastics. I'm designing for 500-4000 RPM with hefty torque to use with 3-12mm end mills.

Anybody have an idea if these type motors will deliver decent torque at 500 RPM?

Adam

Jonathan
01-12-2011, 06:07 PM
Anybody have an idea if these type motors will deliver decent torque at 500 RPM?

Not unless you either rewind the motor to get a lower kv, or use belts, which you are doing. Still 500rpm is pushing it with one belt reduction. I think you'd need two. My brushless motor spindle is a big 12 pole motor, so it's quite slow - but still 6000rpm on the full 50V. Eleven to one reduction isn't happening with one belt, but 3:1 to get max 2000rpm would probably be fine with that motor. You would only get about a quarter of the power out of that motor, but a quarter of 6kW or so is still plenty!

njhussey
01-12-2011, 08:50 PM
Well bought the motor today, got a 320kV one http://www.giantcod.co.uk/xyh5065-320kv-brushless-outrunner-p-404606.html so hope to have that early next week! Still waiting for my bearings from the US, been over a month now :-(

Still will give me a chance to finish off the bearing housing!

blackburn mark
01-12-2011, 10:19 PM
My intent is primarily to machine aluminum and hard plastics. I'm designing for 500-4000 RPM with hefty torque to use with 3-12mm end mills.

Anybody have an idea if these type motors will deliver decent torque at 500 RPM?

Adam

i dont cut with a 12mm endmill however i do cut a lot of acetal/delrin and a bit of alli with the larger of these spindles(250kv) 2.5mm to 6mm + fly cuting without any major problems, i personally believe you would struggle to make use of any more low speed power/tourque without having your gantry shake rattle n roll :eek:

thats asuming your going to run it on a router ?

i just had a look at where you live to see if it was worth nipping over to you so you could try one :lol: san francisco !!! thats a looooooong way LOL :smile: sorry man

blackburn mark
01-12-2011, 10:24 PM
Well bought the motor today, got a 320kV one http://www.giantcod.co.uk/xyh5065-32...-p-404606.html (http://www.giantcod.co.uk/xyh5065-320kv-brushless-outrunner-p-404606.html) so hope to have that early next week! Still waiting for my bearings from the US, been over a month now :-(

Still will give me a chance to finish off the bearing housing!


that looks a much better choice motor than i made for my C8 spindle... i think mine is 980kv

njhussey
05-12-2011, 02:49 PM
Well got the motor today :smile:
5009
Flipping bearings still have not arrived....think they've bneen lost in transit as now 5 weeks...:thumbdown: still the seller said they'd expedite another shipment...

Mark,

did you put a groove in the ER collet shaft for the circlip or not?

Villacherman
05-12-2011, 04:44 PM
Mark,

Well I will be over in your timezone in December for a couple weeks visiting wife's family, I suspect Newcastle isn't all that close to you all, however.

Thanks for the input, yes it will be a gantry router type design. I have a minimill that I'm making parts on and that's relatively low RPMs (up to 2000).

What RPM do you use the flycutter at?

Neil- maybe me bringing the bearings over and sending them through you post system would be faster! Any other parts hard to get there? Belleville washers?

Adam

njhussey
05-12-2011, 05:12 PM
Neil- maybe me bringing the bearings over and sending them through you post system would be faster! Any other parts hard to get there? Belleville washers?

Adam

It can't be any slower Adam!!! Thing is I want these as they are 22mm OD which is better as the motor mounting bolt holes are 3mm dia on a 30mm PCD which only leaves 2.5mm wall thickness.

Belleville washers are ok, I've found a couple of suppliers and Mark kindly said he'd give me enough if I was struggling!

Gonna crack on with the bearing housing now and wait for the bearings...

blackburn mark
05-12-2011, 09:29 PM
did you put a groove in the ER collet shaft for the circlip or not?

no.... my thoughts where that the tight fit (bearings n housing) would hold it all in place, iv had no problems so far using the double row a/c... i did have an issue with one my C8 spindle bearings (cheap skate bearings/bad fit on the shaft) resonating the inner race around the shaft at certain speeds so i used a bit of epoxy on that and its been ok so far.... now i think about it i guess the bellville washers become redundant once the glue has set and when the bearings wear i might get some slop ... it may need some further thought


What RPM do you use the flycutter at?



hi adam... iv not measured rpm's for a while however im pretty sure i skim acetal at 1500rpm and aluminium at less (maybe 1000rpm) thats with a 30mm radius fly cutter

with aluminium i have to be pretty careful (light cuts) or i get resonance patterns but im pretty certain thats my gantry sides and not my spindle

i should really do a test to see how low i can take the rpm and still cut with the fly cutter but iv never seen the need as iv allways got by at those speeds

njhussey
06-12-2011, 03:13 PM
Dissassembled the motor, worryingly there was no locktite on the grub screw holding the body onto the shaft....needless to say there will be when it goes on the collet :naughty:

Am ashamed to say :redface: that for the first housing I'm cheating and getting someone else to machine the housing as they have offered to do it for nothing (our local machinist we use at work) in between jobs they are currently doing...which is very nice of them. I'll use the other bits I've started to do a smaller high speed spindle for engraving

At some stage I'll re-wind it as the winding is poor and also the potting/epoxying of the magnets wasn't too clever either as some was proud and was rubbing on the armature. Still you get what you pay for so I shouldn't be too surprised I guess...

5016

Villacherman
06-12-2011, 04:23 PM
Neil,

Does the rewinding take much effort? That's to change the v/RPM?

I'm waiting to see how things go with yours to start mine, looking forward to it! :)

Adam

njhussey
06-12-2011, 05:25 PM
Adam, I don't know how much effort it will take. I'll do it to tidy up the winding (see photos) as it's not very neat but will not bother at first as I want to get the spindle up and running first!

Jonathan
06-12-2011, 05:58 PM
You'll find lots of info on rewinding this type of motor on the rcgroups forum. If it works fine I wouldn't worry ... but if you want to change the number of turns to get optimal kv then it's got to be the way to go.

I wouldn't say you've got what you paid for when you paid more than the going rate for that motor:

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=4913

I've not had any from hobbyking with poor magnet potting...but I've only bought about 10 and not the one you got.

njhussey
06-12-2011, 11:41 PM
Jonathan - Yeah you save yourself about £5 but have to wait 2 - 3 weeks, I bought mine on Thursday night and it was delivered to my works (no Sat deliveries) Monday am, you won't get that with Hobbyking :wink: One of these days I'll pluck up the courage and order something from there :tup:

Turnigy motors are good motors, I've had a few in my planks and only had a couple of issues (loose magnets and noisy bearings.)

njhussey
13-12-2011, 08:10 PM
Single AC bearings finally arrived today, this is the second lot as the first lot never made it...

Run out of time to do the spindle this side of Xmas as off visiting relatives after the end of this week till the New Year!

Villacherman
15-12-2011, 09:37 PM
Neil,

Sorry, I'm on lunch at work so I didn't have time to look through the thread... you are putting one bearing in front and one in back (of the housing which is out front of the motor), correct? What type of fit are looking for on 1) the shaft and 2) in the housing. Press fit I'm assuming, but roughly how much force?

I'm assuming this will cause some pre-load on the bearings... and with more interference on the fit, the more preload on the bearing.

Have a good holiday... anything I should not miss up in Newcastle? I'll be there for a couple weeks...

Adam

njhussey
23-12-2011, 02:35 AM
Hi Adam, not been on here for a while as work was mad (trying to get a quote out and clear my desk) last week, 57 hour week...

I've tried the bearings on the ER16 collet shaft and they are disappointingly a loose sliding fit...will be a light press fit (heat housing first and slide the back bearing in) in the housing with Bellville washers pretensioning the inner races. Will have to locktite one bearing to the shaft and I guess leave the other a loose fit to keep the pretension? If the bearing starts skidding on the shaft (like Mark's did) then I'll have to locktite that too I guess.

I don't know Newcastle or the surrounding area, never been to that part of the country yet, so can't help you on what not to miss I'm afraid!!

Hope everyone has a Merry Christmas & a Happy New Year!

Swarfing
20-02-2012, 10:27 PM
Hey guys how is this thread progressing?

Jonathan
20-02-2012, 10:46 PM
I'm working on one with two brushless motors, ATC and water/oil cooling. It will be a while until I post the build log, but my prototype for the ATC works. Having difficultly sourcing disc springs/Belleville washers though...

Swarfing
20-02-2012, 10:49 PM
http://www.leespring.com/uk_index.asp?CountryCode=011

njhussey
24-02-2012, 09:29 PM
Jonathan, I found these people http://www.bellevillesprings.com/belleville-washers.html and was quoted 100 off D18842 for £15 (min order charge else would have been £10.33) with P&P £5.50.

Progress as far as I'm concerned has ground to a halt at the moment as our lathe at work is poorly at the moment...

HankMcSpank
26-02-2012, 01:03 PM
DIY spindle porn...

http://www.dieselrc.com/projects/cncspindle/

blackburn mark
26-02-2012, 01:46 PM
DIY spindle porn...


very posh !

a lot of work in one of those :eek:

njhussey
16-05-2012, 05:44 PM
Far better than mine...wow has it been that long since I last looked at this....been too busy spending money on RC helis.

Bought a small boring bar and today in lunch bored the inside of the bearing holder out. Tomorrow will face off (parting tool not big enough) the part to the correct dims. Then just need enough Bellville washers to fill a 12mm gap...that offer of some washers still on Mark? ;)

Last bit is the cap then fit it all together...will take pics later!

blackburn mark
17-05-2012, 10:28 AM
that offer of some washers still on Mark? ;)


itll cost you some pictures of where you are up to and how it works out with those 208 AC bearings

PM your address and the gap you have between your bearings

njhussey
18-05-2012, 03:41 PM
6009601060116012Here you go Mark...pics from lunchtime's machining. The Ali has been in the bottom of a box of all my CNC bits from when I moved 2 months ago so is looking a bit worse for wear. If I can be bothered I'll skim the surfaces once it's done to tidy it up!

Villacherman
23-05-2012, 02:16 PM
Neil,

Looks like it's coming along!

I've had a shake up here as well, lots of my toys are still in boxes. Was laid off, found a job, moved from California to Michigan (~2300 miles!), bought a house... phew, that makes me tired all over again thinking about it!

Here are some pics of my copycat spindle design, I think I'm in the same spot of the build as you are Neil.

6032603360346035
6036

I'm using a Turnigy G110 motor, two 8x22x7 angular contact bearings, 4 belleville washers, and an er11 collet with 8mm shank. I'm mostly going to use this spindle for light work: plastics, engraving, PCB cutting, etc.

I'm a little concerned the bearings will heat up, any thoughts on this?

Also, did you re-install the e-clip ring onto the new shaft?

njhussey
23-05-2012, 03:03 PM
Neil,

Looks like it's coming along!

I've had a shake up here as well, lots of my toys are still in boxes. Was laid off, found a job, moved from California to Michigan (~2300 miles!), bought a house... phew, that makes me tired all over again thinking about it!

Here are some pics of my copycat spindle design, I think I'm in the same spot of the build as you are Neil.

6032603360346035
6036

I'm using a Turnigy G110 motor, two 8x22x7 angular contact bearings, 4 belleville washers, and an er11 collet with 8mm shank. I'm mostly going to use this spindle for light work: plastics, engraving, PCB cutting, etc.

I'm a little concerned the bearings will heat up, any thoughts on this?

Also, did you re-install the e-clip ring onto the new shaft?


Looking good, I couldn't get the holding nuts in the housing as the PCD of them is too close to the 22mm centre hole. I'm going to have a real session on it this weekend as for once I'm in Hereford and not got anything planned (although if it continues to be sunny like predicted I'll be out up the field with my RC helicopters :nevreness: ) and as June will be a write off as I'm out every weekend :thumbdown:

I think the bearings will get warm, what speed are you going to be running it at? blackburn mark or Jonathan will be the ones to ask as they use theirs! If it gets too hot I'll use the router it to cut a water cooling jacket for it :nevreness:

I'm not going to bother turning a groove for the circlip as I reckon that the grub screw (I'll drill a small recess in the shaft) will hold it as well as some locktite :)

Looknig forward to seeing pics of the finished spindle!

Jonathan
23-05-2012, 03:55 PM
6035

Unless I'm missing something obvious the collet chuck shaft isn't actually fixed axially to the angular contact bearings?
The outer rings of the angular contact bearings are fully constrained by the housing and axial force from the Belleville washers, however neither of the inner rings are attached to the shaft, so the two angular contact bearings are effectively acting as just a standard radial bearing with zero clearance. Currently when the shaft is subjected to an axial force it would move, except for the grubscrew and bearings in the motor - so it is those standard bearings in the motor that are actually resisting the axial force which defeats the object of using angular contact bearings.

You need to somehow fix the inner ring of the angular contact bearings to the shaft - best way is probably to machine a fine thread on the shaft and use a locknut (rather like on ballscrew mounts). You then have both bearings facing the other way round and place the Belleville washers between the nut and bearings and use the nut to apply a known preload by measuring the compression distance of the springs. This is how I've done it on a ballscrew... same principle applies. The problem is the shaft will be hard to machine so someone will suggest you simply locktight the lower bearing to the shaft, but that's rather crude.

The preload required must be greater than the maximum axial cutting force and greater than the minimum load specified by the following formula:
http://www.skf.com/portal/skf/home/products?maincatalogue=1&lang=en&newlink=1_3_10
This avoids sliding friction within the bearing which will lead to excessive power dissipation and thus heat build-up. However equally you don't want to use more preload than necessary as clearly that will also cause the bearing to heat more. You could machine slots into the housing with a parting tool to make fins so the greater surface area increases heat dissipation. Even better, make a channel in the housing (or mount) and pump water through it.

njhussey
23-05-2012, 04:43 PM
Unless I'm missing something obvious the collet chuck shaft isn't actually fixed axially to the angular contact bearings?

If the fit of the bearings on the ER11 shaft aren't a press fit then there would be a problem. I've just discovered my bearings slide up and down the shaft!

Isn't the spindle up pressing up against the inner race of the lower bearing? So wouldn't this mean that any axial load is applied to the inner race of the lower bearing and the Bellville washers would transmit the load to the upper bearing?

Jonathan
23-05-2012, 05:10 PM
If the fit of the bearings on the ER11 shaft aren't a press fit then there would be a problem. I've just discovered my bearings slide up and down the shaft!

If the bearings were a press fit the belleville washers wouldn't do anything - you must have a sliding fit so that the springs can apply a preload.


Isn't the spindle up pressing up against the inner race of the lower bearing? So wouldn't this mean that any axial load is applied to the inner race of the lower bearing and the Bellville washers would transmit the load to the upper bearing?

Yes for an 'upwards' axial force it's constrained - but not downwards. If it wasn't for the normal bearings and grubscrew the shaft could just fall out.

Villacherman
23-05-2012, 07:10 PM
Thanks for the replies...

How about if I add a shaft coupling to the stop with a couple of belleville washers? Then using the collet head pressed up against the lower bearing inner race and the shaft coupling, you would get your axial constraint.

I would also load the angular contact bearing in the same orientation (both loaded with "upward" force). This would make the bearings strong in plunge operations, but weaker in operations where the bit is moving up out of the work piece. Would this be a problem though? Most operations are pressing into (down) the work piece.

6037

njhussey
23-05-2012, 08:13 PM
If the bearings were a press fit the belleville washers wouldn't do anything - you must have a sliding fit so that the springs can apply a preload.

Ok, yes I can see that.


Yes for an 'upwards' axial force it's constrained - but not downwards. If it wasn't for the normal bearings and grubscrew the shaft could just fall out.

How does the motor work with a prop on it in a plane then? There is a circlip to stop the shaft pulling out if the motor is used as a pusher or reverse mounted but nothing to stop it being pulled out apart from the bearings and the grub screw as you say. This seems to be enough for a model so I'd have thought it would have been enough?

Maybe if I machine 2 steel collars 8mm ID and 10mm OD and secure them with grub screws (locktited in of course!!) one above the top bearing and one below the bottom then that would stop the movement? Would the grub screws be strong enough?

I'll do a drawing later as on the mobile...

Jonathan
23-05-2012, 08:32 PM
[QUOTE=njhussey;30976
How does the motor work with a prop on it in a plane then? There is a circlip to stop the shaft pulling out if the motor is used as a pusher or reverse mounted but nothing to stop it being pulled out apart from the bearings and the grub screw as you say. This seems to be enough for a model so I'd have thought it would have been enough?[/QUOTE]

On a plane the magnitude axial force (thrust) from the motor is much smaller than in our application, plus accuracy (end-float, radial clearance etc) is pretty much irrelevant for just spinning a propeller. The bearings will wear out much faster than if they used angular contact beraings, but the cost isn't justified. If sufficient axial force is applied to a deep groove bearing the balls will ride up the sides of the rings outside of the superfinished races on to the rougher (relatively speaking) area of the ring, causing increased wear.

I'll reply to the rest when you've done a drawing...

blackburn mark
24-05-2012, 01:16 AM
i personaly wouldnt get to bogged down in all the rocket science... make sure you get some tension in your balls and make sure your shaft cant easily rotate in the bearing bore (loctight the nose bearing if its a tad slack) and all should be fine

any slack will result in balls skidding or a sypathetic rolling rotation/vibration between your shaft and your bearing bores
(a very short life span for either and poor finishes)
iv used super cheap skate bearing on my er11 with aprox 2kg of tension between the two and its still going strong
if you get any high pitched squeals/squeaks etc when the spindle runs up or down you need to fettle

the beauty of these spindle is they are cheap n simple
iv seen threads on diy spindles that are works of art and that have followed the theory to the letter, however, i get good finishes in acetal and alli so seen no point in getting all posh if the aim of the game is to get yourself up and cutting :)

PS: your bellville washers are bagged n ready neil, i just need to get off my arse and post them :(

blackburn mark
24-05-2012, 01:51 AM
I would also load the angular contact bearing in the same orientation (both loaded with "upward" force). This would make the bearings strong in plunge operations, but weaker in operations where the bit is moving up out of the work piece. Would this be a problem though? Most operations are pressing into (down) the work piece.


on most occasions your tool would be pulling down as you are cutting but as i have said above, get some tension in those balls and and loctight your nose bearing and you should be fine

bearing heat may be an issue if your running above 10000rpm (keep an eye on the temp though as it may take a while for your bearings to settle in) if your cutting plastics and pcb's and your not in a crazy arsed rush then 10000rpm is a tad fast... i cut acetal at between 2000rpm and 4000rpm (6mm 3mm tooling) im sure i read somewhere that anything up to 110 degree C and your ok .... mine dont get anything like that hot

the small engraving spindle i made gets pretty hot when i run it above 30000rpm so i tend to run it closer to 20000rpm , i dont run that one very often so its hard to say how long the bearings will last?

njhussey
24-05-2012, 12:06 PM
I'll reply to the rest when you've done a drawing...

Well I've had a look at the design and tewaked it a bit. Will probably do a MK2 spindle using this method or I might tweak this one I've already machined. this one is only really going to be cutting up to 6mm balsa and 3mm ply so I can't imagine the forces as being huge. I might stretch to some delrin/acetal and even try some Ali for a laugh :smile:

6038

This shows the top collet (but I haven't bothered showing the grub screws) on the 8mm shaft which is pre-loading theinner races against the bottom collet. I'm guessing I could get away with not securing the bottom collet (locktite) as it will be trapped between the bottom bearing inner housing and the ER16 collet.

6039

This shows the assembled unit (minus the bolts but we all know what they look like!!)

6040

The bearings in the above are not spaced the correct distance, they will be a further 10mm apart so I can get some Bellville washers in between.

This design has the inner races locked to the 8mm shaft and the outer races are constrained by the endcaps...............comments?

njhussey
24-05-2012, 12:10 PM
PS: your bellville washers are bagged n ready neil, i just need to get off my arse and post them :(

Cheers Mark, no huge rush as I've still got lots to do on the router (everything apart from the base!!) which I'm hoping to break the back of over the weekend.

Villacherman
24-05-2012, 08:36 PM
Neil,

I like the design. Is there enough wall thickness of the collar (8mm ID X 10mm OD) to accommodate a small screw?

What about a collar that has a thicker wall and a little standoff, like this... gives you more meat to tap into.

6047

This could also allow for a more tortured path on the bottom collar to keep dust out.

My last comment is to not forget to think about how you will assemble this... go through the steps in your mind, sometimes I design something and find out I can't assemble it because there are inaccessible features! :(

Adam

Villacherman
25-05-2012, 02:14 PM
I just figured out grub screws are 4-40 set screws... I'm learning everyday!

Neil, was the shaft of the motor hard to swap out for the collet shank? Anything I should not do? I want to give it a try this weekend. I'll do all the usual, keep things straight and support, remove the circlip, etc...

njhussey
25-05-2012, 02:38 PM
I just figured out grub screws are 4-40 set screws... I'm learning everyday!

I'd be using 2 off M2 x 3 grub screws and locktite in each collar (will prob make it 3mm thick for extra purchase of the grub screws) as per the attached photo.6048


Neil, was the shaft of the motor hard to swap out for the collet shank? Anything I should not do? I want to give it a try this weekend. I'll do all the usual, keep things straight and support, remove the circlip, etc...

I removed the circlip and pulled the bell off the motor complete with the shaft. Then put the bell on the vice so the shaft was between the jaws but the bell resting on top (obviously with a cloth on the jaws to stop marks) and using a 6mm piece of steel I had lying around gently tapped the shaft out of the bell (obviously remove the retaining grub screw first!!) slid out fine!

I've not put the collet shank in the housing properly yet (although I did fit it slightly on to see how it spum :smug:) as I'm waiting to make the bearing housing first. Been far too busy at work this week to do any machining in my lunch :grumpy: but hoping to get it done next week. This weekend I'll be making my router gantry sides and trying to get that sorted although I keep changing my mind on how to do it!!

rnr107
26-05-2012, 09:19 AM
Hi blackburn mark,
Looks very interesting concept! :-)
I just have 1 question so, How do you get the original shaft out of the motor?
Is it fitted with an interference fit to the bearings?

Ta,
RNR

Villacherman
26-05-2012, 02:50 PM
Rnr107,

I just removed the shaft yesterday on my Turnigy G110 outrunner motor, so this is specific to my motor, others will vary...

1) remove the 4 M3 screws from the propeller mount.
2) remove the e-clip (circlip, retaining clip, however you want to call it) from the side of the motor with the shaft sticking out.
3) pull the shaft out by hand (I've heard you may need more force on other motors)

That's it! I really like the G110 for its simplicity in this manner, though it is a little pricier.

Adam

njhussey
26-05-2012, 03:08 PM
Hi blackburn mark,
Looks very interesting concept! :-)
I just have 1 question so, How do you get the original shaft out of the motor?
Is it fitted with an interference fit to the bearings?

Ta,
RNR

Hi rnr...most are sliding fits but as with all Chinese mass produced manufacturing will vary from motor to motor...mine is a medium sliding fit :-)

rnr107
26-05-2012, 09:30 PM
Thanks Adam , Neil! I think I will give it a go, It looks very interesting! :-)

Laurent

paul.hunaban
19-06-2012, 11:56 AM
I want to change out my wood router for a brushless spindle as I’m having to replace the brushes all too often.
What you guys have done here is very interesting but I’m not sure how to size the motor / what motor to get.
Therefore I have a few questions:
Q1, if the RPM/v is rated at 295 does this mean for every volt it will increase by 295 revs, i.e. for 20v the speed would be 5,900 revs?

Q2, would you read the power output in the same context as you would a wood router, i.e. if both were 1000w would both be deemed to have the same output?

Q3, Any recommendations for motor to cut wood (Oak) ? At the moment I do a lot of 3D profile work thus cut at around 2.5m per min.

Q4, should I give any consideration to the speed control other than it meets the spec of the motor, ie is there a rule of thumb for the control to have say a 10% high power rating?

Many thanks in advance Paul

Jonathan
19-06-2012, 12:24 PM
1) Yes that's right.

2) Hard to say - the ratings for the brushless motors are a bit optimistic since they assume excellent cooling from the very high airflow present in a model plane. What power rating the motor is will be dictated by the speed rating since 'hobby' brushless motors with a similar kv specification tend to have similar power ratings. That's unless you introduce a belt into the system...or couple multiple motors on one shaft, but that's probably taking it too far for machining wood.

3) Clearly depends on the tool diameter, but I'm guessing you'll want about 12000rpm for oak? So look for a motor with around that speed rating. Ideally you don't want to have to use 'high voltage' (i.e. above 25V) ESCs as they're very expensive. So roughly 12000rpm/25v=480kv, or more if run from a lower voltage...

http://www.hobbyking.com/hobbyking/store/__18125__Turnigy_Aerodrive_SK3_5055_430kv_Brushles s_Outrunner_Motor.html

Your next problem is the shaft diameter - the one above is only 6mm which makes it a bit useless unless you have a lathe to modify/make a collet chuck...

5) Easier to advise once the motor is chosen, but it's sensible to get a bigger one than rated to be sure. They're pretty cheap from the site I linked to above.

paul.hunaban
19-06-2012, 01:08 PM
Jonathon, thanks for the speedy reply.
I’ve just order from Hongkong the 100a motor control plus a drive module so that’s dealt with. I’m not too concerned about the shaft / collet holder / bearings as I will hand that off to my brother to sort (although he does not know it yet!) and he’s tooled up for the job.
As to the power supply, seems your suggesting a 24v, how about the amps? I’m not sure how the PWM supply to the motor is translated for the source.
Regards Paul

routercnc
19-06-2012, 01:43 PM
The motor linked to above is rated to 70A which should match OK with the 100A SC. In theory this would give 1920watts (24v x 70A) which sounds enough to machine wood. The actual amps pulled (for a given motor) will depend on the cutting load, but I'm not sure how easy this is to calculate. If you pull too many amps during the cut the SC will probably pop.

For this reason myself and other model aircraft users often use an ammeter to check the current draw on the ground for a given prop to make sure all is well before the first flight. If the SC gives up in the air, since it sometime also powers the reciever you loose the plane.

You could do the same thing for the first cuts to check your safety margin.

paul.hunaban
19-06-2012, 02:55 PM
Yep power output would easily do the job. But, given the supply will be PWM then this shall have a resultant affect on the current drawn, dependant on speed required / length of pulse. What I hoping for is the input from those members who are now using these brushless motors to cut wood to help by letting us know from their experience, motors used – power supplies etc. I will poach with pride!! I’m happy to be told information resulting from experience as it does not always relate to theory...
Regards Paul

Jonathan
19-06-2012, 04:24 PM
Power supply is tricky (unless you have a large budget) since 70 amps is a pretty large current:

http://www.ebay.co.uk/itm/HOT-Universal-AC-to-DC-Converter-24V-20A-480W-Switching-Power-Supply-Adapter-/200745773845?pt=UK_Computing_LaptopAccessories_Pow erSupplies&hash=item2ebd616b15#ht_2890wt_1037

£40 for 20A .. not great, but there's another way. If you place a battery which can deliver the peak load in parallel with the ESC&PSU then the PSU only needs to supply the average current. This is where it's easiest to just measure how much current the motor draws when cutting and get the PSU to match. A standard multimeter wont measure 70 amps since they tend to be fused at 10-20A. Something like this is excellent as you can measure the current and it records the peak current:

http://www.hobbyking.com/hobbyking/store/__10786__HobbyKing_HK_010_Wattmeter_Voltage_Analyz er_.html

Or the cheap way is to use a multimeter to measure voltage across shunt resistor, which can just be a short length of wire of known resistance. I used one of the following batteries, with a 0-50V, 0-20A lab PSU in parallel on mine:

http://www.hobbyking.com/hobbyking/store/__9262__Turnigy_3000mAh_6S_20C_Lipo_Pack_Great_for _T_Rex_500_.html

That battery is rated for 60A constant, or 90A for 10 seconds which is plenty. Since my PSU has variable voltage output and current limiting I can set it to just below the fully charged voltage of the battery (i.e. <22.2*4.2) and it will never overcharge the battery, which is very important since overcharging a lipo battery is a good way to start a fire. So whatever PSU you get if you decide to use in combination with a battery will need to have good stable voltage regulation below 25.2V. Two computer ATX PSUs (http://www.ebay.co.uk/itm/NEW-500W-SATA-MOLEX-4-Pin-CPU-ATX-PSU-PC-COMPUTER-POWER-SUPPLY-UNIT-/261046062841?pt=UK_Computing_PowerSupplies_EH&hash=item3cc78ecef9#ht_3169wt_1037) in series is nice and cheap and will give very close to 24V, however it is CRITICAL to ensure they are electrically isolated before putting them in series. The battery would never fully charge, but that's a good thing if anything as it increases it's life expectancy. You could get the battery first, use it to power the motor to measure the current then buy a PSU to suit.

We can estimate what power you require; what cutter diameter and depth of cut do you generally use (at 2.5m/min presumably)?

For example:

12mm cutter, 2.5m/min and 60% stepover at 6mm depth of cut is 108cm^3/min material removal rate (12*0.6*2.5*6=108). That's about 740W required...and a pretty rigid machine to sustain that. So you'd ideally want a PSU rated for a bit more than that to be safe. Also it's a good idea to put better capacitors on the ESC, especially with such long wires, to reduce the impedance...

Hopefully it'll turn out the motor draws a lot less current and you can just use a standard PSU.

paul.hunaban
19-06-2012, 08:52 PM
Jonathon this is really good stuff, please keep it coming.

So if I’ve understood this correctly, you are running a 70A motor supplied by a 20A power supply supported by a battery for peak current demands? What voltage do you have the supply set at?

I trust you are controlling the motor via a speed controller, I’ve ordered this one today “100A Brushless Motor Speed Controller” but just realised it has an input voltage of 22.5, which may now give me an issue.
Speed controller purcahsed from ebay: http://www.ebay.co.uk/itm/160631166740?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

I don’t understand your translation from the material removal rate of 108cm^3/min to the 740w motor requirement. Can you please explain or point to a source of information. Frankly I’m surprised a 740w motor will cut that much, I actually cut with a 6mm cutter and no deeper than 2mm with a 500w router (anything else frightens to much!!), so what would the motor requirement be for 18cm^3/min (6*0.6*2.5*2=18).


Thanks paul

Jonathan
19-06-2012, 09:30 PM
I'm actually running a 120A, 130kV, 6.5kW rated (yeah right) motor from a 100A ESC, currently on my micro lathe but I have used it on the router - somewhere in this thread. This motor is good up to 50V, so I should use a HV ESC to get the full speed but I've not got round to buying one. The rigidity of the micro CNC lathe limits the power draw somewhat as it's not rigid enough, so it will only draw a few hundred watts. If I use the motor at a low speed with a big drill it could be more. I leave the PSU at about 24.5V, but it's really not critical so long as it's not above 4.2 volts per cell (i.e. 6*4.2=25.2V). It's nice to have the lab PSU, but it's not worth buying one just to power a spindle. Down to about 23V would be fine as far as the battery's concerned.

The listing for the ESC states 22.2V - this is because they expect people to use Lipo batteries, which are nominally 3.7 volts per cell so a 6 cell battery is 22.2V. However when fully charged the same battery will be 4.2*6=25.2V, so the ESC will withstand 4.2V. Since it's a cheap one it would be prudent to run a little below that.

I read somewhere that hardwoods take about 7W/cc/min to cut, so 108*7=756W. That makes 18cc/min about 18*7=126W. Bear in mind since this is motor output power we need to include the efficiency of the motor.

The motor I linked to was based on 12000rpm, but with a 6mm cutter you could be using almost twice that? I've cut some hardwood, not sure what it was, with a 6mm single flute carbide cutter at 6m/min and 6mm depth of cut and 20000rpm. However if you're machine can only manage 2.5m/min then a lower spindle speed is fine, but perhaps aim for 18000rpm? Although having said that the motor is most efficient when at maximum speed.

Anyway, if it's 126W and even if we double it to make sure, at 250W then you've got plenty of options for the PSU. At that power the battery is hardly necessary, but it would make a very robust system if you did have one. I'd mount the battery and ESC on the Z-axis as close as you can to the motor to keep all the wires short, then have long wires from the PSU to the motor. This will make the ESC run more efficiently, i.e. cooler and in extreme cases can make the difference between it surviving and not.

m_c
20-06-2012, 01:47 AM
Jonathan, have you ever had any problems with cell balance using a LiPo?
I'm just wondering how actually using a multicell pack without balancing it works out longer term, as my current project needs a 2cell pack, and I'm trying to decide if I really need to include a balancer circuit.

Jonathan
20-06-2012, 02:42 PM
Jonathan, have you ever had any problems with cell balance using a LiPo?
I'm just wondering how actually using a multicell pack without balancing it works out longer term, as my current project needs a 2cell pack, and I'm trying to decide if I really need to include a balancer circuit.

Not had a problem, except when the battery is already on it's way out. With a 2 cell battery I doubt you need to bother with balancing.

m_c
21-06-2012, 02:13 PM
Not had a problem, except when the battery is already on it's way out. With a 2 cell battery I doubt you need to bother with balancing.

It's one of these things that gets mentioned alot, but not sure how much difference it's going to make in practice. I'm probably going to at least add the circuitry to the PCB as I've spare ADC pins on the uC anyway, and might built a couple prototypes with and without the extra components just to see what happens. I'm aiming for longetivity, so it may be a case of every little bit helps!

vtcnc
11-09-2012, 03:51 PM
That battery is rated for 60A constant, or 90A for 10 seconds which is plenty. Since my PSU has variable voltage output and current limiting I can set it to just below the fully charged voltage of the battery (i.e. <22.2*4.2) and it will never overcharge the battery, which is very important since overcharging a lipo battery is a good way to start a fire. So whatever PSU you get if you decide to use in combination with a battery will need to have good stable voltage regulation below 25.2V. Two computer ATX PSUs (http://www.ebay.co.uk/itm/NEW-500W-SATA-MOLEX-4-Pin-CPU-ATX-PSU-PC-COMPUTER-POWER-SUPPLY-UNIT-/261046062841?pt=UK_Computing_PowerSupplies_EH&hash=item3cc78ecef9#ht_3169wt_1037) in series is nice and cheap and will give very close to 24V, however it is CRITICAL to ensure they are electrically isolated before putting them in series. The battery would never fully charge, but that's a good thing if anything as it increases it's life expectancy. You could get the battery first, use it to power the motor to measure the current then buy a PSU to suit.

Thanks Jonathan for this very helpful information. I hadn't realized that it was possible to connect ATX PSUs together in series to increase voltage -- just assumed they were regulated in a way that would prevent this. Makes sense really, when I think about it. Battery cells have nominal voltages and can be series connected into a battery of higher voltage. Somehow I got hung up on the regulated part of it.

Anyway, I've gone ahead and ordered two ATX supplies with 12V 30A outputs, and looking forward to making a 24V supply with them for a spindle PS. I will isolate the negative buss from the case, and I know about setting up the switch line and adding a starting load resistor on the 5V lines to keep the supplies running.

I build and fly R/C planes, so I'm familiar with the rest of the motor side components. I have two 5055 1500W rated motors -- one 400 kV and one 540 (I believe) -- both have 8mm shaft dia. I have an 8mm ER-11 collet spindle, and collets.

ps. I also wanted to post a possible correction to the above -- I think the bolded text above should read "(i.e. <6*4.2)"

Thanks for your PSU info!

vtcnc
11-09-2012, 11:20 PM
(deleted and prior post corrected)

njhussey
10-10-2012, 01:19 PM
Made some progress on this after concentrating on helis for the last goodness knows how long. The amount I've spent on helis recently I probably could have built a reallt top notch router by now.....oh well still having fun with the helis so not too worried :D

Anyway....below is the progress I've made with the spindle housing, will dig out the bits from the box in the cupboard tonight and see if I can put it together tonight (minus the bellville washers as I've forgotten to order them!!)

7095709670977098

njhussey
10-10-2012, 07:51 PM
Here it is roughly assembled....I know the shaft is sticking down by 12mm ish as I've not put it all the way in the motor bell, see last pic! I'm waiting on getting some Bellville washers then I can finish it off :)

7102

7103

7104

Tenson
11-10-2012, 01:28 PM
Brilliant work :)

What is your PSU?

blackburn mark
11-10-2012, 02:42 PM
I'm waiting on getting some Bellville washers then I can finish it off :)

i could have sworn i sent you some

njhussey
11-10-2012, 11:14 PM
Brilliant work :)

What is your PSU?

I can't take any credit as I followed what blackburnmark did, ok I adapted it a bit but the principle was the same :)

I'm going to be using one of the cheap 40A 24V psu's from eBay...

njhussey
11-10-2012, 11:21 PM
i could have sworn i sent you some

B***er...can't remember getting any...I did move house back in March tho so maybe they're there?

blackburn mark
12-10-2012, 11:06 AM
i think they where sent in may... PM sent

njhussey
12-10-2012, 03:10 PM
PM replied to Mark.....

I've got 150 off P188207 Belleville Washers coming early next week so think I should have enough for this and any other spindle I might be wanting to do :D

m.marino
12-10-2012, 10:09 PM
Question to you guys is how well do the DC motors handle heat when running at different RPM's? Also would setting up a PID type closed loop controller work with a DC motor? Looking at options with one of the other members and a DC brush-less motor is looking like the best option for providing the need power and from the looks of it the needed RPM's as well. Has anyone though of side mounting the motor and connecting it via belts to the spindle (possibly using a key way to help lock the pulleys to their spindles). This would some variance in torque and from what I can see would really make the spindle have a rather wide range of uses.

Just asking as kicking around ideas and designs and these are points that have run across. Anyone happen to know a source for variable speed AC motors in the 1.5kw range that don't cost the moon or come from questionable quality control?

Michael

Jonathan
12-10-2012, 10:26 PM
I'm not sure if you're referring to the motors discussed in this thread, which are brushless AC motors, or normal DC motors? Either way a PID control algorithm can be used to improve the performance. A DC-servo motor is just the motor with encoder and PID control for position and speed.


http://www.youtube.com/watch?v=ghDez-3dpWs

blackburn mark
14-10-2012, 02:50 PM
Question to you guys is how well do the DC motors handle heat when running at different RPM's?

I’v had no issues with motor heat... i could confidently push my spindles much harder if I needed to.
Where i do have concerns is the ESP (speed controller) they do get hot... iv not blown one yet but i bought a spare because i thought i might with the amount of heat they push out (no problems though so far) at £20 (ish) its silly not to have a spare.

with a 12v 350w power supply the majority of my spindles are vastly under the “claimed” potential and iv not once thought I needed more power/torque… im sure our honorable speed freak friend Jonathan would want more speed n torque (you would need the extra speed if you wish to cut wood…I’m cutting plastic 90% of the time, I don’t cut any wood at all)

if your cutting wood and alli/plastics its worth weighing up if making two spindles is easier than dealing with pulleys on one ?

njhussey
14-10-2012, 10:21 PM
Most model ESCs are mounted where there us some airflow (the ones I have in my planes all have air ducts directing air onto them and the one on my Trex 500 heli is on the side so in the downdraught) so I'll be putting a 24V fan by mine for cooling.

http://img.tapatalk.com/d/12/10/15/abyze9y8.jpg

Belleville washers arrived today but just back in from a weekend away so will be tomorrow before I complete the spindle now :)

Jonathan
17-10-2012, 11:23 AM
Most model ESCs are mounted where there us some airflow (the ones I have in my planes all have air ducts directing air onto them and the one on my Trex 500 heli is on the side so in the downdraught) so I'll be putting a 24V fan by mine for cooling.

A fan does make a big difference to the ESC (not ESP! :playful:) temperature - I put fans on the ESC(s) in my model car for the same reason. A lot of model car ESCs include fans now since the airflow tends to be poor in that application.
Bit off topic, but is that a genuine T-rex or did you get a cheap copy (http://www.hobbyking.com/hobbyking/store/__11445__HK_500CMT_3D_Electric_Helicopter_Kit_incl _GF_blades_and_extras_.html)? I got the latter, but can't say I've used it much yet as I always seem to have other things to do...

How much did all those springs cost?

njhussey
17-10-2012, 09:08 PM
It's a genuine Trex 700 nitro, don't think HK do a copy....yet ;)

The main reason I've not got further with this project is I've probably spent 2.5k on helis in the last 18 months to the exclusion of everything else!

They cost £15 + the dreaded and P&P so I think approx £25 in total...still got about 130 left :)

njhussey
17-10-2012, 10:08 PM
Bit off topic, but is that a genuine T-rex or did you get a cheap copy (http://www.hobbyking.com/hobbyking/store/__11445__HK_500CMT_3D_Electric_Helicopter_Kit_incl _GF_blades_and_extras_.html)?

Just realised I'd said I had a Trex 500 in my text....yeah it's a genuine one...my Avatar is the 700...I did buy a HK450 but it's a bit like buying a router made from MDF with unsupported rails lol

njhussey
19-10-2012, 10:12 AM
Assembled the spindle last night...well tried to anyway! Found that the Belleville washers don't compress much so you have to be careful how many you use otherwise you load the bearings too much.

Went to assemble it and put the motor bell back on and was putting the last bolt in when I noticed that it was a bit stiff. I bought a pack of 5 off SS 40mm long M4 bolts and on the first assembly used 4 and then obviously used the spare bolt when doing the final assembly. Took the offending bolt out and noticed that the first thread was damaged so I've only gone and flipping cross threaded 1/3 of one of the motor mounting holes grrrrrrr.......got to find my tap now and see if I can re-tap it and clean things up. Failing that I'll drill the cross threaded bits out and just use the rest of the thread with lots of threadlock!!

Will get it up and running tonight and power it from my Trex 500 for a test as I've not got the power supply and ESC for it yet.

njhussey
02-11-2012, 08:59 PM
Had the spindle running tonight, coupled it up to my Trex 500 esc...it works!!!

7295

http://www.youtube.com/watch?v=3yaSpBq44uo&amp;feature=youtube_gdata_player

njhussey
08-11-2012, 10:27 PM
Mark, you've got some smaller spindles haven't you? How have you done them? I want to make a smaller powered one but one that runs much quicker to cut balsa, but on looking the smallest shank of an ER11 collet holder is 8mm and I don't want to be messing around turning the shank down to 5 or 4mm if I can help it!

Jonathan
08-11-2012, 10:32 PM
How have you done them?

Look for motor with 1/8" shaft, buy 1/8" shank cutter, replace shaft with cutter...

njhussey
08-11-2012, 10:54 PM
Look for motor with 1/8" shaft, buy 1/8" shank cutter, replace shaft with cutter...

Cheers Jonathan, I looked at that but I was looking to do one if possible where I can change the tool without having to remove it from the motor. I was having a look to see if there was anything out there like a pin vice that could be used but thought I'd float the question.

I've got a Proxxon E50 that I was originally going to use but thought I'd go back down the brushless motor route.

Jonathan
08-11-2012, 11:05 PM
I was having a look to see if there was anything out there like a pin vice

Runout

You might be able to do something like drill and ream/bore a 1/8" hole and hold the cutter in with a grubscrw. The force on the cutter will be very small, so it should hold perfectly well.

blackburn mark
08-11-2012, 11:14 PM
I was having a look to see if there was anything out there like a pin vice that could be used but thought I'd float the question.

I've scoured the earth looking for a good quality pin vice type thing... it drove me up the wall... i even did a search for ER3 collets lol ... alas... there is no such thing :(
I considered making my own but that is now on my "things to do in the next life list"

give us a shout if you find anything "posh"
i'm pretty sure it would cost a bomb if you find anything of quality out there
its a dam shame

njhussey
08-11-2012, 11:27 PM
I'm rapidly coming to the same conclusion Mark...there are pin vices out there that could be used but as Jonathan says...runout! Saying that for my balsa needs I could live with 0.25mm.

Saying that I've been thinking of going down the DIY laser route today. Could make a real lightweight router then ;)

Jonathan
08-11-2012, 11:28 PM
Looks like ER8 is the smallest:
New Straight Milling Shank C10 ER8 100L Collet Chuck | eBay (http://www.ebay.co.uk/itm/New-Straight-Milling-Shank-C10-ER8-100L-Collet-Chuck-/280718724586?pt=BI_Tool_Work_Holding&hash=item415c23cdea)

The thing to do is have a go at making your own ER8 or ER11 collet chuck.


going down the DIY laser route today. Could make a real lightweight router then ;)

I'd love to see a router made with a laser...

njhussey
08-11-2012, 11:58 PM
Might have a look at making my own collet chuck to take the Proxxon collets...but there again I might just as well use my Proxxon :)

blackburn mark
09-11-2012, 12:08 AM
Might have a look at making my own collet chuck to take the Proxxon collets...but there again I might just as well use my Proxxon :)

ahhh, yes... but will it run at 48000rpm :)

njhussey
09-11-2012, 12:11 AM
Erm....no 20,000 is it's limit. What you running a 4000kV motor??!!

blackburn mark
09-11-2012, 12:39 AM
Erm....no 20,000 is it's limit. What you running a 4000kV motor??!!

eerm, yea its 4000kv but I tend not to run it passed 20000rpm if I'm honest... it might be fine flat out but I don't like it :)
iv got tons of spare bearings so I should go for glory and the fun of science and run it till it grinds to a halt but I never do

njhussey
09-11-2012, 12:46 AM
On my next spindle I'm going to cut the housing in layers (done on the Router) and have some water cooling to keep things cool. Looking at work to see what the smallest air blast cooler I can get is...

I've got lots of bearings too, comes from having lots as spares for the RC helis ;)

blackburn mark
09-11-2012, 12:57 AM
air blast cooler
sounds posh ?
what is it ?

njhussey
09-11-2012, 01:01 AM
Basically a car radiator with fan and motor, like this:

7356

blackburn mark
09-11-2012, 01:12 AM
Basically a car radiator with fan and motor, like this:

7356

now that is POSH!
splendid :)

Point25
18-02-2013, 01:06 PM
Hello folks,

Many thanks for sharing all this info, it has inspired me to build a spindle based on a 5045 motor & ER11 8mm spindle :-) I have a couple of questions though which I hope arn't too simple !!

- The bearing arrangement is along the lines of: for the chuck/housing interface a pair of Angular Contact (AC) bearings with 4 pre-load washers between them? And for the housing/motor interface a standard roller bearing? Where would be a good place to buy the AC bearings with matching pre-load washers (either UK or eBay).... any spec available so I know what to ask for?
- I'm guessing the AC bearing assembly needs to sit proud of the housing before the cover plate clamps it all in place - how much of the bearing should be proud?
- I am looking at 24V power supplies and wondering if I need to have one large power supply to run both the NEMA17 steppers and the spindle of if I should really split this into 2 suppies with about 5A @ 24V for the steppers and 20A @ 24V for the spindle?

Thanks for any tips :-)

blackburn mark
18-02-2013, 07:36 PM
belleville washers
708a bearings, these are a bitch to find at the moment so a search for magneto bearings would be my second choice

I'm sure mine has about 1kg of tension (on standard skate bearings) still runs ok but doesn't get used much compared to the larger ones... if your going to hammer it to death angular contacts makes sense and would need even less tension/pre-load than the skate bearings to perform the same task

I run all my spindles at 12v (350w power supply... its never tripped)
the 100A ESC gets pretty hot but the motors are fine at that
if your cutting wood and need the extra speed you will have to stick your neck out and let us know how you get on


I'm guessing the AC bearing assembly needs to sit proud of the housing before the cover plate clamps it all in place
mine was about 1mm proud... maybe a touch less


bearings with 4 pre-load washers between them?
i think there is 8 or 10 in mine, so with only 4 you want to be approx 0.5mm proud or less, it depends on your washers

you could get really technical and do the maths but you would need to know your typical cutting force triple it, pray to the moon god and add some fairy dust :)

having at least some tension stops the bearings skidding and self destructing but if your cutting force or resonance overcomes the tension you will get a shit finish

Point25
18-02-2013, 10:37 PM
Thanks for getting back to me Mark, much apprecited.

The Magneto Bearing looks ideal and avoids the need to install belleville washers by the looks of it? If going down this route would I use one magneto bearing between the chuck and housing and one standard bearing between the housing and motor?

I am hoping to cut wood but perhaps starting with an old computer ATX power supply will let me feel my way into the power question - sounds like this might be waht you are using.

Jonathan
18-02-2013, 10:50 PM
You require two magneto/angular contact bearings and they need to be pre-loaded, hence Belleville washers are mandatory, unless you can find a matched pair of bearings but that wont be cheap. There are sellers with 8mm angular contact bearings on Aliexpress.com - Online Shopping for Electronics, Fashion, Home & Garden, Toys & Sports, Automobiles from China. (http://www.aliexpress.com)

Point25
18-02-2013, 11:38 PM
Thanks Jonathan - looks like finding the Belleville washers is going to be the hardest part, wonder why they are so rare.

I have spoken with www.simplybearings.co.uk (http://www.simplybearings.co.uk) but they need to know more tech info to allow them to advise - any idea what I should be asking for.... or perhaps there is another (afforable :-) bearing in their range which would get round the Belleville washer requirement?

Point25
01-03-2013, 07:28 PM
Hi, I now have what I think I need - 2 Magneto Bearings and some Belleville washers :-).... now just wondering how to arrange the bearings and washers in relation to oneanother?

Do I put the 2 bearings back to back - ie with their 'open' faces both towards the inside and the washers separating them?


Thanks.

blackburn mark
01-03-2013, 11:29 PM
iv never looked at the implications I think back to back is the standard but id fit them in which ever way was easiest to implement
I had to make a couple of washers with a grove in the face for the outer Belleville springs to sit in to keep them central and clear of the shaft

I "think" I pulled tension on the inner races via the spindle.... errr, no hang in, I used epoxy to lock one of the races.... bollocks! I cant remember now? when you have all the parts in your hands you'll make sense of it

tight fit on the pointy end bearing (housing and the shaft) and allow the other bearing to float to some extent so the Belleville washers can overcome any movement (if that makes sense)

EDIT: i assumed "back to back" meant open ends out?

Point25
02-03-2013, 01:24 PM
Thanks Mark,

I think I have this assembled right but thought I would post some pictures to confirm and help others who have the same question.

I didn't quite get what you were saying about fixing the washers - I guess the aim is to center them to stop them rubbing on the spindle - seems like that might be quite difficult?

Cheers.

83168317

blackburn mark
03-03-2013, 03:32 AM
I think you where right in you description of "back to back" sorry :(
you are pushing the inner races apart
as long as the bearing closest to the tool end is tight on the shaft and in the housing I'm guessing all will be well

....now I think about it the inner races shaft and spring washers will all rotate which may be a good reason to go "face to face" because if the washers aren't perfectly central they will cause resonance at high revs

"face to face" would mean the washers don't spin with the shaft as they push against the outer races
that's why I remember "pulling the shaft" so to speak

with the springs between the outer races you need to grip the shaft to hold the tension... in my case I simply used the out runner bell to grip the shaft and hold the tension (not good for your outrunner bearings) what I should have done is add a collar with grub screws, I did have one but I hadn't accounted for the extra room it would take inside the bearing housing

if you don't get what I mean let me know and the next time I'm at home ill take some pictures of mine or knock up a drawing

in a nutshell, instead of pushing the inner races apart from the inside you are pushing them together from the outside

you may suss a better way of doing it ?
let us know how you get on

booski
21-07-2013, 05:59 PM
Hi there,

First post here and entirely new.

I just wished to contribute something. For my honours project for my degree, I made a desktop CNC machine.

Part of this project was to produce a simple spindle. To drive it I used a brushless motor, a small thing.

As you know, to control a brushless motor speed you need a servo tester. The trouble is, when you switch a brushless ESC on, you need to wait about 7/8 seconds with the servo tester at full off while the ESC initialises before turning up to the required speed.

Well, I designed my own speed controller using a simple PIC micro controller and program. It's designed as such so that it powers off the ESC's own servo supply. When power is applied to the ESC, the controller starts off at zero ignoring the speed dial for 8 seconds while the ESC initialises. Afterwards, the controller reads the dial and spins up the motor.

It makes the whole thing automatic and requires no manual intervention. Simply a delay from the control software on the host computer to accommodate for the ESC initialisation.

I'm curious whether there's any interest in this sort of thing as more brushless spindles come about? I've not seen anything like it before.

Jonathan
21-07-2013, 06:52 PM
I'm curious whether there's any interest in this sort of thing as more brushless spindles come about? I've not seen anything like it before.

Yes I should think there is, at least for Mach 3 users. A long time ago I made a simple circuit using a PIC12F683 to interface between the parallel port PWM output and a standard ESC. However I didn't use it for long since, in addition to getting a standard spindle, I switched to LinuxCNC for which someone has already written the code to make the parallel port output the correct PWM signal for an ESC.

On a related topic, I recently put the motor I originally made into a spindle on to my Mum's bike. For that I used one of the electric bike speed controllers from eBay and added hall-effect sensors to the motor. As one would expect, it's far better than the sensorless controllers, especially at low speed, so if I was to make another brushless motor spindle I'd definitely control it with a similar controller:

48V/600W brushless controller for E - bike & scooter | eBay (http://www.ebay.co.uk/itm/48V-600W-brushless-controller-for-E-bike-scooter-/300352534034?pt=LH_DefaultDomain_0&hash=item45ee67f612)

They're also programmable, so you can set the current limit among other things, which could be useful for this application. I'll post a picture when I've got it off the other computer...

totts
22-07-2013, 06:47 PM
I use a comtroller from http://www.logicnc.com/rcnc.html

Its a bit strange at picking a speed at times but in a program it seems to run fine, many of hours running with this and enables fully automated control of my brushless spindle.

totts
22-07-2013, 06:50 PM
Also heres a video

http://youtu.be/XKCUqyvt1RA

sergey
30-06-2014, 10:52 AM
Мотор водяного охлаждения OBL29/19 (2375)пойдет под er11

Mod Note: Translated: Engine cooling water OBL29/19 (2375) will go under er11

Lee Roberts
30-06-2014, 11:34 PM
Мотор водяного охлаждения OBL29/19 (2375)пойдет под er11

Пожалуйста, говорите по-английски, поэтому мы можем понять вас.Онлайн-переводчик должен быть достаточно, спасибо.

I think he's trying to point us to this: http://www.amazon.com/Thunder-Tiger-2375-19-15M-Motor/dp/B007KMZ6V4

.Me

PunkR0ckz
12-11-2014, 06:28 PM
Hi guys, I know this is somewhat of an old thread but I registered on this website because of it. I am looking everywhere for those C10, ER20, 100L collet chuck but I can't seem to find one... only found the 50L version and it isn't long enough for the outrunner I bought. I will try reusing this 50L somewhere else, but I need a 100L and was wondering where to get one? I'm trying on eBay, but I can't seem to find any, must be because I live in Canada...

If someone knows where to buy one new C10-ER20-100L collet chuck, please reply to this post, or if you own one and are willing to ship it to me that would be awesome! Thanks a lot and I hope I'll be able to make this DIY since it mimicks exactly what i've been looking to do

Boyan Silyavski
13-11-2014, 04:36 AM
http://m.aliexpress.com/search.htm?keywords=c10+er16+100l&shippingCountry=ES

PunkR0ckz
13-11-2014, 05:04 AM
http://m.aliexpress.com/search.htm?keywords=c10+er16+100l&shippingCountry=ES

This is an ER16 collet chuck, I need an ER20 collet chuck, but thanks silyavski :)
I found some after searching through the posts here but had to modify the link for my region (canada) because it wasnt showing up

Here is the link, for those interested in Canada (might work elsewhere too, but wasnt working for me with a .com.uk):
http://www.ebay.ca/itm/111501420293?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

njhussey
13-11-2014, 02:45 PM
That's the seller I bought mine off....arrived quickly if I seem to remember correctly.

PunkR0ckz
13-11-2014, 03:57 PM
That's the seller I bought mine off....arrived quickly if I seem to remember correctly.

Yup, that link was from you, I just modified the .com.uk to a .ca because it wasnt working for me. I hope it doesn't take too much time to arrive here :)

Metsuko
13-10-2015, 01:54 PM
hi neil, sounds like youll have no problems with the project:smile:

id be tempted to go with an ER11 C8 with a little less overhang

http://www.ebay.co.uk/itm/ER11-8MM-STRAIGHT-SHANK-COLLET-CHUCK-CNC-MILLING-LATHE-TOOL-WORKHOLDING-D66-/150676636475?pt=BI_Tool_Work_Holding&hash=item231507033b

if you compare this with the one you linked i think youll know what im driving at... it may make little diffrence when cutting balsa but when aiming to cut ali every little bit of stiffness you can gain will help (i have cut ali with mine)

iv used cheep skate bearing in my ER C8 spindle... iv used belleville washers to put some tention between the two outer races.... i havnt had to change them yet but it only gets light use

if you dont put any tension on those skate bearings the balls will skid and self destruct pretty quickly

4771
the layout is not to clear in this picture, youll have to let me know if you dont get it :wink:

What is the orange motor name?

Snowy
24-10-2015, 09:51 PM
Hi there,
I'm a complete novice with CNC and aero motors and speed controllers. Does anybody know the bits i'd need to order (motors, KVA and speed controllers all a bit of a puzzle) in the UK that would enable me to build something like this?
Thanks in advance

njhussey
24-10-2015, 09:54 PM
What you trying to cut? This will influence what KV motor you use etc...

Snowy
25-10-2015, 01:03 PM
Hi there,
i'd like to be able to cut alluminium but also softer stuff like plastics and wood. Do you think it could be suitable for steel also? i thought it would be too weedy?

njhussey
25-10-2015, 01:14 PM
You'll never get one spindle to cut everything. Steel needs slower speeds, typically a few hundred rpm up to a couple of thousand, what it really needs is torque and lots of it! Wood and plastic on the other hand need higher rpm and feeds. You're best not thinking about steel on a router and just buying a mill if you want to do steel. In all honesty you're better off buying a 2.2kW water cooled spindle for just under a couple of hundred quid which will do all you want with consument ease...I've got a home made brushless spindle and I've not bothered using it. I will do on something but not sure what yet...

If you still want to make one then use a feeds and speeds calculator to work out what speed and power you want for the materials you're wanting to cut and then look at something like a 5565 brushless dc motor (look on hobbyking) 170kV to 270kV outputting approx 2kW coupled to a 100A ESC.

Snowy
26-10-2015, 08:54 PM
Cheers Neil,
Exactly the kind of info i'm needing
Snowy

PunkR0ckz
12-10-2016, 11:20 PM
Hi guys, sorry to "revive" this thread, but I would like to know if somebody has been able to control this kind of spindle (outrunner with an ER collet) with an Arduino UNO to be able to achieve precise RPMs? As this would make it much more practical for the kind of use I want to make out of it... if so, how did you achieve it? Would it bother you sending the line of codes / diagram / pictures / videos or anything else to show what you did and all that? I am a newb when it comes down to electronics and really want to achieve this ! Thanks !!

dlang
28-11-2016, 03:56 AM
I use a comtroller from http://www.logicnc.com/rcnc.html


Everything I try to go to on that site asks for a password, is it still live?